Sukat

input/code.cpp:22:6: error: expected initializer before 'MaxList'
   22 | node MaxList(){
      |      ^~~~~~~
input/code.cpp: In function 'int main()':
input/code.cpp:36:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   36 |     for(int i=0;i<s.size();i++){
      |                 ~^~~~~~~~~
input/code.cpp:39:5: error: 'node' was not declared in this scope; did you mean 'Node'?
   39 |     node ml=MaxList();
      |     ^~~~
      |     Node
input/code.cpp:40:11: error: 'ml' was not declared in this scope; did you mean 'll'?
   40 |     while(ml.cnt){
      |           ^~
      |           ll
input/code.cpp:42:13: error: expected ';' before 'sl'
   42 |         node sl=MaxList();
      |             ^~~
      |             ;
input/code.cpp:43:12: error: 'sl' was not declared in this scope; did you mean 's'?
   43 |         if(sl.cnt==0)break;
      |            ^...

#include<iostream>
#include<cmath>
#include<algorithm>
#include<string>
#include<queue>

using namespace std;

typedef long long ll;
typedef long double ld;

string s;
int idx[30];

int ans;
string anslist[200009];

struct Node{
    int cnt,id;
}

node MaxList(){
    node ret;
    ret.id=0;
    ret.cnt=0;
    for(int i=1;i<=26;i++){
        if(idx[i]>ret.cnt);
        ret.cnt=idx[i];
        ret.id=i;
    }
    return ret;
}

int main(){
    cin>>s;
    for(int i=0;i<s.size();i++){
        idx[s[i]-'A'+1]++;
    }
    node ml=MaxList();
    while(ml.cnt){
        idx[ml.id]=0;
        node sl=MaxList();
        if(sl.cnt==0)break;
        ml.cnt=ml.cnt-sl.cnt;
        idx[ml.id]=ml.cnt;
        for(int i=1;i<=sl.cnt;i++){
            ans++;
            anslist[ans]=(char)(ml.id-1+'A')+(char)(sl.id-1+'A');
        }
        idx[sl.id]=0;
        ml=MaxList();
    }
    cout<<ans<<endl;
    for(int i=1;i<=ans;i++){
        cout<<anslist[i]<<endl;
    }
    return 0;
}